Elmer Goris spent a year working in Amazon.com's Lehigh Valley warehouse, where books, CDs and various other products are packed and shipped to customers who order from the world's largest online retailer.

The 34-year-old Allentown resident, who has worked in warehouses for more than 10 years, said he quit in July because he was frustrated with the heat and demands that he work mandatory overtime. Working conditions at the warehouse got worse earlier this year, especially during summer heat waves when heat in the warehouse soared above 100 degrees, he said.

He got light-headed, he said, and his legs cramped, symptoms he never experienced in previous warehouse jobs. One hot day, Goris said, he saw a co-worker pass out at the water fountain. On other hot days, he saw paramedics bring people out of the warehouse in wheelchairs and on stretchers.

"I never felt like passing out in a warehouse and I never felt treated like a piece of crap in any other warehouse but this one," Goris said. "They can do that because there aren't any jobs in the area."

Goris' complaints are not unique.

Over the past two months, The Morning Call interviewed 20 current and former warehouse workers who showed pay stubs, tax forms or other proof of employment. They offered a behind-the-scenes glimpse of what it's like to work in the Amazon warehouse, where temperatures soar on hot summer days, production rates are difficult to achieve and the permanent jobs sought by many temporary workers hired by an outside agency are tough to get.

Only one of the employees interviewed described it as a good place to work.

Workers said they were forced to endure brutal heat inside the sprawling warehouse and were pushed to work at a pace many could not sustain. Employees were frequently reprimanded regarding their productivity and threatened with termination, workers said. The consequences of not meeting work expectations were regularly on display, as employees lost their jobs and got escorted out of the warehouse. Such sights encouraged some workers to conceal pain and push through injury lest they get fired as well, workers said.

During summer heat waves, Amazon arranged to have paramedics parked in ambulances outside, ready to treat any workers who dehydrated or suffered other forms of heat stress. Those who couldn't quickly cool off and return to work were sent home or taken out in stretchers and wheelchairs and transported to area hospitals. And new applicants were ready to begin work at any time.

An emergency room doctor in June called federal regulators to report an "unsafe environment" after he treated several Amazon warehouse workers for heat-related problems. The doctor's report was echoed by warehouse workers who also complained to regulators, including a security guard who reported seeing pregnant employees suffering in the heat.

In a better economy, not as many people would line up for jobs that pay $11 or $12 an hour moving inventory through a hot warehouse. But with job openings scarce, Amazon and Integrity Staffing Solutions, the temporary employment firm that is hiring workers for Amazon, have found eager applicants in the swollen ranks of the unemployed.

Many warehouse workers are hired for temporary positions by Integrity Staffing Solutions, or ISS, and are told that if they work hard they may be converted to permanent positions with Amazon, current and former employees said. The temporary assignments end after a designated number of hours, and those not hired to permanent Amazon jobs can reapply for temporary positions again after a few months, workers said.

Temporary employees interviewed said few people in their working groups actually made it to a permanent Amazon position. Instead, they said they were pushed harder and harder to work faster and faster until they were terminated, they quit or they got injured. Those interviewed say turnover at the warehouse is high and many hires don't last more than a few months.

The supply of temporary workers keeps Amazon's warehouse fully staffed without the expense of a permanent workforce that expects raises and good benefits. Using temporary employees in general also helps reduce the prospect that employees will organize a union that pushes for better treatment because the employees are in constant flux, labor experts say. And Amazon limits its liability for workers' compensation and unemployment insurance because most of the workers don't work for Amazon, they work for the temp agency.

Amazon's priority and key competitive edge is quick delivery of products at low prices. Its Lehigh Valley location on Route 100 near Interstate 78 puts one-third of the population of the U.S. and Canada within a one-day haul. And the weak labor market helps keep employment costs down.